/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/
function fun(item) {
  let p = new Promise((resolved, rejected) => {
    setTimeout(() => {
      resolved(item);
    }, 10);
  });
  return p;
}

fun()
  .then(function () {
    return fun("hello");
  })
  .then((value) => {
    return fun(value + "lagou");
  })
  .then((value) => {
    return fun(value + "I ♥ U");
  })
  .then((value) => {
    console.log(value);
  });
